Brake-testing apparatus



INVENTOR.

59H 9 1930- M. R. zl-:CHLIN BRAKE TEST-ING' APPARATUS Filed may n25, 192'/ z sheets-snm 1 Sept 9, 1930- M. R. zEcHLlN u1,775,541

BRAKE TESTING APPARATUS Filed May 25, 1927 `2 Shoots-Sheet 2 IN VEN TOR.

i o ing repair work.

Patented Sept. 9, 1930 PATENT oFFlcE mx mmoLrzEcHLm, or DETROIT, MICHIGAN :anexa-TESTING hermanos.,

Application led Hay 25, 1927. Serial No."194,111.

The effect of automobile brakes, at the present time, is tested 'in the way that the distance is measured at which the car stops on the road after it ,has been run 'with av a certain speed and after the brakes have been applied. It is obvious that this method is rather rough, as it is almost impossible tofix the limits of vthis distance in an accuratemanner and as 1t does not lpermit determination of the single eiiectand braking condition ofl each of the two or four wheel brakes. My invention improves thismethod by directly and exactly measuring the frictional resistance of each brake so that their individual effects and eiliciencies can be-compared, and so that they can be adjustedaccuratel to equaliie the braking power uponeac of *l V them. Moreover this` can be done in the garage without moving the car.

For this endv I usean aparatus that is att-achable to `any car wheel. After the wheel hasbeen lifted` so that it clears the floor, a

gear, operated by hand or machine, revolves the wheel to which the brake is applied, by

the'mediation of a reduction gear in order to overcome the frictional resistance4 of the brake, vA torque measuring device, consisting of a yielding device (t. i., a spring) is inserted between the driving and the ydriven a0 parts ofthe gear or the wheel, wherebyv the relative v4revolving `anglev between both is shown on a dial connected to oneof the parts by a hand connected to one of the other parts. As the'whe'elfhas to belifted the apparatus may be combined with a jack that, at the same time, forms the reaction support for the-driving partsof. the gear andthatcan used also to lift the car forchan'gin'gtires or do- An instancejof this apparatus in Figs. 1 to 12 of theannexed .drawingslf when attached to the wheel before li Fig. 2-is AA. Y A ,5. l Fig. 3 is a rear elevation after the wheel., has been lifted, ready to measure the torque necessary to turn the wheel.

Fig. 4 shows a different position of the key lever which locks both legs of the jack after. the wheel has been lifted.

Fig. 5 shows adilerent location of the spring close to the'driving crank.

Fig. 6 demonstratesthe pawl and ratchet eifect of the spring.

Figs. 7 and 8 show an electric measuring device replacing the spring.

Figs. 9 and ltlshow an attaching device of the apparatus, whereby it is fastened to 6o the tires of the wheel.

Figs. 11 and 12 demonstrate another attaching device, whereby wedges are applied proper to fit into the space betweentwo adjacent spokes.- Y c5 Therefore the apparatus consists of these units:

A reduction gear, a torque measuring device, a device to fasten the apparatus to the car wheel and a devicev for lifting the wheel. p.

The following is a detailed specification: Figs. 1 to 4: vThe apparatus consists of a gear carrying housing l with a supporting stationary leg2secure'd thereto and another leg 3 pivoting round the boltft which is as- 75 tened tothe armshield 26. The-leg 3 is locked to leg 2 by a key-lever 5 which is fastened to the leg-3 pivoting about a pin 6 as shown in Fig. 4. In this position the apparatus is moved to the car in order to attach it on the so wheel 7 This is done by connecting the arms Sof the armshield 26 to the rim 9 of the wheel b using the existing bolts and nuts 10.

The riving part of the lifting and wheel revolvingV device consists of a crank 11, a a5 worm 12 and a worm gear 13 the hub of which is hollow and is extended to the rear where i .it is connected to a right hand and a lft hand spiral spring 14 `and 15 in the way that either the one or the. other islocked to the 90 hubof'the worm gear by a projecting'part .'16 or 17 while 'the worm ear 1s revolvin F1a-1 1S a front elevatwn Otthe appetatPS-aeaher in one Orjin the' OtiiegrA direction. 'rh

y Pgtf: outer endsof thesprings are 'connectedto-a a vertwatsetwn along1118.911119.1mmll is which is made integral with the an spur-gear shaft 19, that is supported in the v, hollovi'f' hub'v of the worm gear.v The front end' otthisf shaft ,hasa hand 20 attached., thereto. -`Af vlia"l. 21; is fastened to the worm gear. The yieldingeiect of the spring causes' 100 a relative angular motion between the hand and the dial, which is used for measuring the resistance torque of the driven parts. The latter are, besides the drum 18, a spur gear 22 which is in mesh with a larger gear 23 that is fastened to the armshield 26, forming a revolving unit which pivots round the bolt 4. This bolt is carried in a hub 24 forming part of the pivoting leg 3 and being made of the crankshaft li5-revolving integral with it. This hub 24 is carried in a bearing of the housing l. The latter is provided, on its leg 2, with rollers 25 and 26, and the leg 3 is provided with rollers 27 and 28 in order to move the apparatus with the least effort. A tooth segment 25 is riveted to the center part of the armshield 26 that can be connected to the leg 3 by putting the key lever 5 into the position shown in Fi 2.

fter the arms 8 of the armshield are fast.- ened to the wheel by the bolts 10 and after the key lever 5 has been put into the position shown in Fig. 2, the crank will be turned, whereby the power is transferred through the worm gear, the spring, the spur gear, the tooth segment and the key lever to the leg 3, and whereby this leg is moved toward the leg 2, both legs approaching each other. Thereby the Wheel is lifted, and the appan ratus comes to the position shown by Fig. 3 so that there is enough clearance for the wheel to rotate free of the ground.

Now the key lever 5 is put into the position shown by Fig. 4, i. e., the worm gear being self locking so that the gear cannot reverse and thewheel cannot drop, the key 5 locks the leg 3 to the leg 2 and releases the gear parts. By further turning the crank the wheel, having the brake applied thereto, can be revolved. The braking resistance causes a deflection of the spring which is shown on the'dial by thel hand. AThe size of the an le, ina certain scale, indicates the amount 0% torque necessary to overcome the brake friction.

The arrangement of one left hand and one right hand spring allows the testing of the brake when the wheel is rotated in either direction.

Figs. 7 and e show the appiiation of an* electric device as a yielding member between,

the driving and the driven arts. A genera-` tor yarmature 34 is fastene to the rear end between'po/les 36. The current generated y turning th crank is transferred to'thearmature? fastened to the front end of the crank shaft which revolvesbetween poles 38 forcing the latter to revolve due to A.the electromagnetic ten- 'l sion between them'fThe'pole housing 38 is lmade integral l vvith'lthe worinv39 so that fthe revolving movement v is v transferredto A the reduction gear and to the carjWheel, when 'the crank 40 is turnedlffThis A,orankhas aj hand 41 movingcon a. dialfastened tothe pole housing 38. The resistance of the brake delays the rotation of the pole housing 38 with reference to the revolving velocity of the crank. This delay is shown by the angular difference between the -hand and the dial.

The way of attaching the gear to the Wheel by using the rimbolts l0 or the hub bolts of a disc wheel can be varied in the manner that the gear may be attached to the spokes of the wheel or to the tires, as demonstrated by Figs. 9 to 12.

Figs. 9 and 10 show wheels 7. The armshield 44 .has three arms and it is made integral with the gear 45 corresponding to the gear 23 in Figs. 1 and 2. These three arms form the guides for the three clamps 46, 47 and 48 which grasp the tire. They are provided each with piloting bolts or pins 49 .and 50, which are pilotedfin ova'lcut-outs 51 and 52 of the shield. .The outer curve of the cutou-t 51 is shaped inthe way that, whilel turning the` shield in the 'one or the other direction the bolt 49 and through itt-he clamp 48 is moved radially towardthe center of the wheel whereby the clamping ofthe tire is effected and the apparatus is fastened in a solid manner to the wheel. The bolt 50 has elpough clearance in the cut-outto `allow the s ield to be revolved' at a certain angle, just enough to clamp the tire.

Thesame crank andfreduction' gear which operates the apparatusf'for lifting the wheel and testing thebrakes is Iusledto revolve the shield 44 relatively to Itheclanps' 4647 and 48 to attain their grasping effect on the tire.

Figs- 1l and l2 demonstrate' .a similar vmethod of attaching. the apparatus to the wheel, whereby three wedge shaped parts 53, 54 and F:u'e.'f forced between the spokes of the wheel. These wedges are made integral with parts 513,57A- and 58 which are'guided` by the arms,y of the armshield 59 in the same way as describes with Figse and y1o. whenfhe armshieldlis revolved by 4the reduction gear these wedges are moved radially toward the center of the wheel, whereby they come ,to a press-fit with the spokes and fastenV the apparatus solidlyi to the'1wheel. i i

.This apparatuspan also be used to determinefthe Wheelladi-Dg and the weighty of `/gear forliftingthe wheeler the car isin/direct proportion to the loadf-'fto be lifted. .Thereforelanother scalecan'be provided on the 'dial showingl theiveight of the lifted part, asshownin Fig., 8.

f lClaims:

lf.- Ay brake testing apparatus` ofthe class described, Vcomprising incombination, means forrotating awheel; means for. measuring thev torque resistanceof said wheel; and means operable pri-or tothe Aoperation of said ,rotating means for.` raising'and supporting said wheel ina lifted position, and for subsequently operating said torque measuring means. y

2. A brake testing apparatus of the class described, comprising: a reduc-tion gearing; means for connecting said reduction gearing to a vehicle Wheel; a lifting device; a torque measuring device; and common means for operating said lifting device and said torque measuring device.

3. Abrake testin'g apparatus of the 'class described, comprising: a supporting member; a leg rigidly attached to said member means tor attaching said supporting member to a vehicle Wheel; means for causing said leg -to approach the vertical subsequent to attachment for raising said Wheel clear of its normal supporting surface; torque measuring means; means for rotating sald Wheel; .and means for transmitting the resistance of said Wheel to said torque measuring means.

4. A brake testing apparatus of the class described, comprising: a` supporting mem-y ber; relatively moving supporting .legs

mounted on said supporting member, said legs heilig normally inclined and spread apart; means for attaching said supporting member to a vehicle Wheel; means for bringing said legs into closer approach for raising said wheel clear of its normal supporting surface; meansfor rotating said Wheel While in lifted position; and torque measuring means operable upon the rotation of said Wheel for measuring the torque resistance thereof.

5. A brake testing yapparatus of the class described, comprising: a supporting member; a diagonally extending, depending leg on said supporting member; aA leg swingably mounted on said supporting member and normally spread apart from said lirst leg means for attaching said supporting member to a vehicle Wheel; gearing and means operable upon the rotation of said gearing for moving said legs into approach and raising said Wheel clear of its normal supporting surface; means for rotating said wheel; .means for locking said legs in fixed relation during the rotation of said Wheel; torque measuring means; and means for transmitting the torque resistance of said'wheel upon rotation thereof to said torque measuring means.

6. A brake testing apparatusof the class described, comprising: a lifting device;

means for connecting vsaid lifting device to` a vehicle wheel; a torque measuring device;

and common means for operating said lifting device and said torque measuring device.

MAX RUDLF ZECll-HJN. 

